mirror of
https://github.com/qgis/QGIS.git
synced 2025-02-23 00:02:38 -05:00
1513f0ab93
We are now using the code from "qgis" branch: https://github.com/hobu/untwine/tree/qgis It is in sync with "main" branch of untwine as of today, just with a couple of small patches to make it work with PDAL older than 2.4. The new version of untwine includes: - indexing to COPC (in addition to EPT) - fixes to bugs that were reported in QGIS - error reporting Untwine now also directly links to lazperf library (in addition to PDAL).
68 lines
1.9 KiB
C++
68 lines
1.9 KiB
C++
|
|
#include "Stats.hpp"
|
|
|
|
#include <cmath>
|
|
|
|
namespace untwine
|
|
{
|
|
|
|
void Stats::computeGlobalStats()
|
|
{
|
|
auto compute_median = [](std::vector<double> vals)
|
|
{
|
|
std::nth_element(vals.begin(), vals.begin() + vals.size() / 2, vals.end());
|
|
return *(vals.begin() + vals.size() / 2);
|
|
};
|
|
|
|
// TODO add quantiles
|
|
m_median = compute_median(m_data);
|
|
std::transform(m_data.begin(), m_data.end(), m_data.begin(),
|
|
[this](double v) { return std::fabs(v - this->m_median); });
|
|
m_mad = compute_median(m_data);
|
|
}
|
|
|
|
// Math comes from https://prod.sandia.gov/techlib-noauth/access-control.cgi/2008/086212.pdf
|
|
// (Pebay paper from Sandia labs, 2008)
|
|
bool Stats::merge(const Stats& s)
|
|
{
|
|
if ((m_name != s.m_name) || (m_enumerate != s.m_enumerate) || (m_advanced != s.m_advanced))
|
|
return false;
|
|
|
|
double n1 = (double)m_cnt;
|
|
double n2 = (double)s.m_cnt;
|
|
double n = n1 + n2;
|
|
double nsq = n * n;
|
|
double n1n2 = (double)m_cnt * s.m_cnt;
|
|
double n1sq = n1 * n1;
|
|
double n2sq = n2 * n2;
|
|
double ncube = n * n * n;
|
|
double deltaMean = s.M1 - M1;
|
|
|
|
if (n == 0)
|
|
return true;
|
|
|
|
double m1 = M1 + s.m_cnt * deltaMean / n;
|
|
double m2 = M2 + s.M2 + n1n2 * std::pow(deltaMean, 2) / n;
|
|
double m3 = M3 + s.M3 + n1n2 * (n1 - n2) * std::pow(deltaMean, 3) / nsq +
|
|
3 * (n1 * s.M2 - n2 * M2) * deltaMean / n;
|
|
double m4 = M4 + s.M4 +
|
|
n1n2 * (n1sq - n1n2 + n2sq) * std::pow(deltaMean, 4) / ncube +
|
|
6 * (n1sq * s.M2 + n2sq * M2) * std::pow(deltaMean, 2) / nsq +
|
|
4 * (n1 * s.M3 - n2 * M3) * deltaMean / n;
|
|
|
|
M1 = m1;
|
|
M2 = m2;
|
|
M3 = m3;
|
|
M4 = m4;
|
|
m_min = (std::min)(m_min, s.m_min);
|
|
m_max = (std::max)(m_max, s.m_max);
|
|
m_cnt = s.m_cnt + m_cnt;
|
|
m_data.insert(m_data.begin(), s.m_data.begin(), s.m_data.end());
|
|
for (auto p : s.m_values)
|
|
m_values[p.first] += p.second;
|
|
|
|
return true;
|
|
}
|
|
|
|
} // namespace untwine
|